海河北系1956年-2012年降水时序演变特征

采用海河流域北系20个气象站1956年-2012年降水时间序列,从趋势、周期、突变和空间差异四个方面分析了该地区降水时空变化特征。结果显示:海河北系年降水以14.9mm/(10a)的速度减少;降水具有多时间尺度下的显著差异特征:月尺度较平稳,仅10月、11月发生显著下降,5月、6月发生显著增加;季尺度上,春、秋季较平稳,夏、冬季呈现下降趋势;年降雨呈现28年显著周期,并且在20世纪80年代前后转入枯水期。地区差异上,山区较平原区降水变化幅度更大,但周期平稳,突变时间更早。

Characteristics analysis of time serial of rainfall in the northern part of Haihe River Basin from 1956 to 2012

The annual precipitation time series of 20 climate stations in the northern part of Haihe River Basin from 1956 to 2012 were analyzed in this paper. The spatial and multi-temporal characteristics of the rainfall were analyzed from the aspects of trend test, period analysis, breakpoint detection and spatial heterogeneity analysis. The results showed that: (1) the rainfall of the northern part of Haihe River Basin decreased by 14.9mm per ten years; (2) rainfall of different time scales had significantly different characters: the monthly rainfall was steady, with rainfall in October and November decreasing significantly and that in May and June increasing significantly; the rainfall in spring and autumn were relatively stable and the decline in summer and winter were of significance; the annual rainfall were of 28 years period and switched from wet season to dry season in around 1980s. (3) annual rainfall in mountain areas reduced at a rate twice as quick as that in plain areas, but had more solid period and earlier breakpoint.